People tracking by cooperative fusion of RADAR and camera sensors

Accurate 3D tracking of objects from monocular camera poses challenges due to the loss of depth during projection. Although ranging by RADAR has proven effective in highway environments, people tracking remains beyond the capability of single sensor systems. In this paper, we propose a cooperative RADAR-camera fusion method for people tracking on the ground plane. Using average person height, joint detection likelihood is calculated by back-projecting detections from the camera onto the RADAR Range-Azimuth data. Peaks in the joint likelihood, representing candidate targets, are fed into a Particle Filter tracker. Depending on the association outcome, particles are updated using the associated detections (Tracking by Detection), or by sampling the raw likelihood itself (Tracking Before Detection). Utilizing the raw likelihood data has the advantage that lost targets are continuously tracked even if the camera or RADAR signal is below the detection threshold. We show that in single target, uncluttered environments, the proposed method entirely outperforms camera-only tracking. Experiments in a real-world urban environment also confirm that the cooperative fusion tracker produces significantly better estimates, even in difficult and ambiguous situations

Radar and video as the perfect match : a cooperative method for sensor fusion

Accurate detection and tracking of road users is essential for driverless cars and many other smart mobility applications. As no single sensor can provide the required accuracy and robustness, the output from several sensors needs to be combined. Especially radar and video are a good match, because their weaknesses and strengths complement each other. Researchers from IPI – an imec research group at Ghent University – developed a new technique to optimize radar-video fusion by exchanging information at an earlier stage

Bertrand-Edgeworth markets with increasing marginal costs and voluntary trading: Experimental evidence

Price competition with increasing marginal costs, though relevant for many markets, appears as an under-researched field in the experimental oligopoly literature. We provide results from an experiment that varies the number of firms as well as the demand rationing and matching schemes in Bertrand-Edgeworth markets with increasing marginal costs and voluntary trading. We find that prices and profits are substantially higher in duopoly than in triopoly and with proportional compared to efficient demand rationing. The matching rule has little effect on prices and profits. Nash equilibrium predictions do not capture observed behavior. Neither the mixed-strategy Nash equilibria of the underlying one-shot game nor, for the fixed matching condition, the symmetric stationary outcome pure-strategy Nash equilibria of the infinitely repeated game are supported by the data. In contrast to results from related experiments, behavior is largely more competitive than predicted by Nash equilibrium theory. Individual pricing decisions can predominantly be explained by either myopic best responses (Edgeworth cycles) or simple imitative behavior, where the complexity of the decision situation plays a crucial role in which behavioral pattern applies

Reviews

Computers and Typography edited by Rosemary Sassoon, Oxford, Intellect, 1993. ISBN: 1–871516–23–4

Demand rationing in Bertrand-Edgeworth markets with fixed capacities: An experiment

This study is the first to investigate the effect of demand rationing in experimental Bertrand-Edgeworth markets with fixed exogenous capacities. It is found that prices and profits are significantly higher under proportional than under efficient demand rationing. Moreover, the amount of capacity available to each firm is varied. In accordance with earlier studies, prices and profits are significantly higher when capacities are lower. Those effects accord qualitatively with the Nash equilibrium predictions of the corresponding stage games. However, the Nash equilibrium concept does poorly at quantitative predictions. Prices are significantly higher than the Nash prediction in all treatments, irrespective of whether the Nash equilibrium is in mixed or in pure strategies. Profits are higher than the Nash prediction with high capacities, but may converge to the equilibrium prediction in the long run with low capacities. The data of individual price choices feature dynamic patterns that can potentially be explained by both Edgeworth price cycles and imitation of the price set by the competitor

The effects on waiting times of expanding provider choice:evidence from a policy experiment

Long waiting times for inpatient treatment in the UK National Health Service have long been a source of great popular and political concern, and therefore a target for policy initiatives. One such is the London Patient Choice Project, under which patients at risk of breaching inpatient waiting time targets were offered the choice of an alternative hospital with a guaranteed shorter wait. This paper uses a difference in difference econometric methodology to infer the impact of the choice project on ophthalmology waiting times. In line with our theoretical predictions, it finds that the project led to lower average waiting times in the London region and a convergence in waiting times amongst London hospitals.

How should private investors diversify? : An empirical evaluation of alternative asset allocation policies to construct a "world market portfolio"

This study evaluates the out-of-sample performance of numerous asset allocation strategies from the perspective of a Euro zone investor. Besides an increased sample period from January 1973 to December 2008, our contribution to the literature is twofold. First, we compare the performance of a broad spectrum of heuristic portfolio policies with a large set of well-established model extensions of the Markowitz (1952) mean-variance framework. Second, we explicitly differentiate between two prominent ways of diversification that are usually analyzed separately: international diversification in the stock market and diversification over different asset classes. Our analysis allows us to compare and discuss different diversification strategies to construct a "world market portfolio" that is as ex-ante efficient as possible. For international equity diversification, we find that none of the Markowitz-based portfolio models is able to significantly outperform simple heuristics. Among those, the GDP weighting dominates the traditional cap-weighted approach. In the asset allocation case, Markowitz models are again not able to beat a broad spectrum of fixed-weight alternatives out-of-sample. Analyzing more than 5000 heuristics, we find that in fact almost any form of well-balanced allocation over asset classes offers similar diversification gains as even very sophisticated and recently developed portfolio optimization approaches. Based on our findings, we suggest a simple and cost-efficient allocation approach for private investors

Digital Three-Dimensional Atlas of Quail Development Using High-Resolution MRI

We present an archetypal set of three-dimensional digital atlases of the quail embryo based on microscopic magnetic resonance imaging (µMRI). The atlases are composed of three modules: (1) images of fixed ex ovo quail, ranging in age from embryonic day 5 to 10 (e05 to e10); (2) a coarsely delineated anatomical atlas of the µMRI data; and (3) an organ system–based hierarchical graph linked to the anatomical delineations. The atlas is designed to be accessed using SHIVA, a free Java application. The atlas is extensible and can contain other types of information including anatomical, physiological, and functional descriptors. It can also be linked to online resources and references. This digital atlas provides a framework to place various data types, such as gene expression and cell migration data, within the normal three-dimensional anatomy of the developing quail embryo. This provides a method for the analysis and examination of the spatial relationships among the different types of information within the context of the entire embryo

Towards a directed homotopy type theory

In this paper, we present a directed homotopy type theory for reasoning synthetically about (higher) categories, directed homotopy theory, and its applications to concurrency. We specify a new `homomorphism' type former for Martin-L\"of type theory which is roughly analogous to the identity type former originally introduced by Martin-L\"of. The homomorphism type former is meant to capture the notions of morphism (from the theory of categories) and directed path (from directed homotopy theory) just as the identity type former is known to capture the notions of isomorphism (from the theory of groupoids) and path (from homotopy theory). Our main result is an interpretation of these homomorphism types into Cat, the category of small categories. There, the interpretation of each homomorphism type hom(a,b) is indeed the set of morphisms between the objects a and b of a category C. We end the paper with an analysis of the interpretation in Cat with which we argue that our homomorphism types are indeed the directed version of Martin-L\"of's identity types

Losing Sight of the Trees for the Forest? Attention Allocation and Anomalies

This paper tests asset pricing implications of the investor attention shift hypothesis proposed in recent theoretical work. We create a novel proxy for the dynamics of inattention towards firm-specific information and explore its impact on prominent return anomalies. As hypothesized and with all else equal, the proxy positively predicts the post-earnings-announcement drift and negatively predicts the success of momentum strategies. Moreover, it has explanatory power for the profitability of pairs trading, a promising yet widely neglected setting concerned with the relative pricing efficiency of economically linked stocks. Taken together, our findings highlight the importance of time-varying investor attention allocation